Python & XML

Defining Stylesheets

If you are familiar with the Cascading Style Sheets (CSS) specification often used on the Web, you are probably aware that CSS stylesheets can be stored in a separate file, or embedded as a special element within an HTML document. Also, specific styling information can be attached to individual attributes within the document. In this section, we examine the corresponding approaches to using XSLT.

Each of the three ways of using CSS have an analogous technique using XSLT, but the XSLT stylesheets are substantially more powerful. While this discussion refers to some specific XSLT elements and shows several in the examples, it does not expect that you know anything about them. These elements are described in more detail later in this chapter; this section simply introduces you to the ways stylesheets can be written and how that relates to the documents being processed.

Simplified Stylesheets

Simplified stylesheets are more like using the STYLE attribute in HTML documents than anything else, but the similarity is minimal. This approach is somewhat less powerful than using embedded or standalone stylesheets; the xsl:stylesheet element is not allowed since the entire stylesheet is interpreted as the body of an xsl:template element. Many features of XSLT require using additional “top-level” elements (peers of the xsl:template element), so they are not allowed in this context. This kind of stylesheet is more difficult to use when the basic structure of the source document ...